package org.yang.reggie.controller;

import lombok.extern.slf4j.Slf4j;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import org.yang.reggie.common.R;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

/**
 * @author 缘友一世
 * date 2023/7/6-17:59
 * 文件上传和下载
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    /**
     * 文件上传
     * @param file
     * @return
     */
    @Value("${image.savePath}")
    private String savePath;


    @RequestMapping("/upload")
    public R<String> upload(MultipartFile file) throws Exception {
        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID重新生成文件名称，防止文件名重复，造成文件覆盖
        String fileName = UUID.randomUUID().toString() + suffix;

        File dir = new File(savePath);
        if(!dir.exists()) {
            dir.mkdirs();
        }

        file.transferTo(new File(savePath+fileName));
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {
        //输入流，读取文件内容
        FileInputStream fileInputStream = new FileInputStream(new File(savePath + name));

        //输出流，通过输出流将文件写回浏览器
        ServletOutputStream outputStream = response.getOutputStream();
        response.setContentType("image/jpeg");

        int len=0;
        byte[] bytes = new byte[1024];
        while((len=fileInputStream.read(bytes))!=-1)  {
            outputStream.write(bytes,0,len);
            outputStream.flush();
        }
        outputStream.close();
        fileInputStream.close();
    }
}
